1. Field of the Invention
The present invention relates to powered toothbrushes, and more particularly, to a toothbrush having a unique handle and a unique relative positioning of conventional batteries to provide a more comfortable and easier to grip handle resulting in additional oral health benefits to the user.
2. Discussion of Related Art
Toothbrushes provide many oral hygiene benefits. For example, toothbrushes remove plaque and food debris to help avoid tooth decay and disease. They remove stained pellicle from the surface of each tooth to help whiten the teeth. Also, the bristles combined with the brushing motion massage the gingival tissue for stimulation and increased health of the tissue.
Powered toothbrushes have been available for some time. Powered toothbrushes have advantages over manual (non-powered) toothbrushes in that they impart movement to the bristles at much higher speeds than possible manually. They also may impart different types and directions of motion. These motions, generally in combination with manual movement of toothbrush by the user, provide superior cleaning than manual toothbrushes. Typically, powered toothbrushes are powered by disposable or rechargeable batteries that power an electric motor that in turn drives toothbrush head.
Known powered toothbrushes include a brush head with a bristle carrier portion that rotates, oscillates or vibrates in some manner so as to clean the teeth. The bristles, which typically comprise bristle tufts, are generally uniform with one end fixed into the bristle carrier portion and the other end free to contact the surface of the teeth while brushing. The free ends of the various tufts present a surface envelope that is capable of some deformation when the bristles bend. When in contact with the surface to be brushed, the bristles may deform so that the surface envelope tends to conform to the complex surface of the teeth. Human teeth generally lie in a “C” shaped curve within the upper and lower jaw, and each row of teeth consequently has a convex outer curve and a concave inner curve. Individual teeth often have extremely complex surfaces, with areas that may be flat, concave, or convex. The more precise conformation between the bristles and the tooth surface, the more effective toothbrush may be in cleaning, whitening and/or stimulating.
Known powered toothbrushes typically arrange the bristles in a compact conical or cylindrical pattern on a generally circular, disk-shaped bristle carrier. The powered toothbrush heads are traditionally compact, generally oval in shape and heads are produced with a flat trimmed bristle pattern. Alternatively, other head shapes and bristle patterns are available.
One example of a powered toothbrush is depicted in U.S. Pat. No. 5,625,916 to McDougall, which is hereby incorporated by reference in its entirety. Toothbrush shown in McDougall has a disc-shaped bristle carrier. The bristle carrier, and thus the bristles, are driven in a vibrating or oscillating manner. This type of toothbrush is described herein with reference to FIGS. 1A-1C. A toothbrush 5 includes a handle portion 10 at a proximal end of toothbrush 5 and a head 11 at a distal end of toothbrush 5. Handle portion 10 has compartments for containing a powered motor 14 and batteries 15 and 16. Head 11 includes a generally circular bristle holder (carrier) 13. A rotatable shaft 12 extends from the motor 14 to head 11. A shaft coupling 17 may be located along the shaft 12 and configured to provide for the shaft 12 to be separated at a point between the motor 14 and head 11. This permits the shaft to be removed from toothbrush 5, e.g., for cleaning, servicing, or replacement.
Head 11 includes a post 18 that provides a rotational pivot axis for the bristle holder 13 containing bristle tufts 19. The distal end of the shaft 12 has a journal or offset 20 that is radially displaced from the longitudinal axis of the shaft 12, which may be integrally formed therewith. The bristle holder 13 has a slot 22 that receives the offset 20. The offset 20 and slot 22 are configured so as to be oriented toward the intersection of the shaft 12 axis and the longitudinal axis of the post 18. When the motor 14 rotates the shaft 12, the motion of the offset 20 defines a circle about the shaft 12 axis and drivingly engages slot 22 such that the bristle holder 13 vibrates or oscillates about the post 18 axis through a rotational angle A. The rotational angle A is defined by the displacement of the offset 20 from the shaft 12 axis relative to the diameter of the bristle holder 13.
Although powered toothbrushes such as those described immediately above provide advantages over manual toothbrushes, they are subject to various limitations. Providing sufficient power for the toothbrush to operate requires substantial battery power, and consequently size. Typically, these batteries have been provided as a pair of batteries positioned one on top of the other in a coaxial relationship. While this configuration results in a thin handle portion, the handle portion may become unduly long, thus making it difficult for a user to handle the toothbrush.
One attempt to overcome the limitations associated with this battery configuration is to place the pair of batteries in the handle side by side, either along a plane positioned perpendicular to the face of the bristle carrier, or along a plane coplanar with the face of the bristle carrier. Such configurations are shown in FIGS. 2 and 3, respectively. Such configurations, however, limit the ability to shape the handle into a shape that is comfortable to the user and assists in allowing the user to properly grip the handle of the toothbrush. Therefore, a toothbrush including such a restricted battery positioning limits the overall effectiveness of the toothbrush.
Thus, there is a need in the art for a powered toothbrush with a more advantageous handle structure to improve the overall effectiveness of such a toothbrush. There is further a need for such improved toothbrushes to be comparable in manufacturing and purchasing costs as known powered toothbrushes.